1. Field of the Invention
The invention relates to a safety binding for skiing, more particularly a safety binding that is adjustable to receive an article of footwear, such as a ski boot, having support projections of various dimensions, such as thicknesses.
2. Background Information
A safety binding for skiing should allow the release of the skier's boot to prevent injury to the foot in the case of an accidental transverse movement of the boot, which may occur during a fall, for example, or, in general, to protect the foot from injury when the forces exerted on the boot exceed predetermined values.
Safety bindings for the practice of ski touring must meet these release requirements. A ski touring binding must also enable the boot to rotate about a transverse axis relative to the ski, located at the front of the boot during the ascent phases, so that the heel of the skier can move away from the ski in order to exert optimum thrust. Such a binding must also make it possible to dampen substantial torsional forces between the boot and the ski during the descent phases.
The ski touring binding sold by Fritschi Corporation under the name Diamir Freeride includes a plate that is pivotally mounted relative to a front baseplate. The front baseplate is adapted to be fixed rigidly to the ski. The binding also includes a rear baseplate adapted to be fixed rigidly to the ski. The plate is selectively released from, or fixed to, the rear baseplate. A toe piece is pivotally mounted about a vertical axis on the front end of the plate. The toe piece has a body that is laterally elongated to form two wings for supporting the foot transversely. A heel piece is fixed to the rear end of the plate.
The body of the toe piece is relatively compact and is in a relatively raised position; it allows for a fairly substantial pivoting of the plate in the ascent position.
A spring is housed within the front end of the plate. The spring returns the toe piece body toward a position for retaining the foot of the skier. The spring defines the transverse force of the skier's foot beyond which the boot of the skier is released by the toe piece. The boot then pushes back one of the wings and pivots the toe piece body forward until it is released.
The vertical support of the boot by the toe piece is obtained by blocking a front projection between two supports. To this end, the front projection is held between an edge of the body forming an upper stop and a support surface arranged in the plate and forming a lower stop. Ski touring boots and downhill ski boots have front projections of different thicknesses. To enable this binding to be used with both ski touring boots and downhill ski boots, the toe piece body is mounted to slide vertically relative to the plate. The rotation of an adjusting screw makes it possible to lower or raise the toe piece body with respect to the plate.
This binding does not guarantee optimum guiding of the ski in the descent position. Indeed, the support of the plate forming the lower stop is at a distance of 40 millimeters (mm) from the surface of the ski in order to facilitate forward pivoting of the plate. The ski boot is then held in a relatively raised position, which is unfavorable for controlling the ski, i.e., unfavorable to the guiding and steering of the ski. No known solution has made it possible to lower the support of the plate without affecting the space requirement of the toe piece and the ability of the toe piece to tilt in the ascent position.
Furthermore, ski touring bindings and downhill ski bindings have functional and operational constraints leading to quite different designs. It is thus difficult to design components common to these different bindings, which limits the possibility of economies of scale during manufacture.